A Good Idea
by R.L. Woodson
Summary: Sam is desperately, hopelessly in love with both his big brother and an angel of the lord. After some moping and an incident with a peep-hole, Dean and Cas remedy the situation. Wincestiel.


**Title:** A Good Idea

**Rated:** M

**Summary:** Sam is desperately, hopelessly in love with both his big brother and an angel of the lord. After some moping and an incident with a peep-hole, Dean and Cas remedy the situation. Wincestiel.

**A Good Idea**

Castiel and Dean had always had their profound bond. It was only a matter of time before the Righteous Man and the angel of the lord would admit the love they shared to each other. They were perfect together; Cas' calm balanced out Dean's anger, and Dean's fun-loving nature balanced out Cas' seriousness. They were completely in sync, just like Dean and Sam were. Had been. Sam didn't know anymore.

Sam had felt everything he imagined love to be and more for his older brother after a particularly vicious wraith fight when he was twelve. At twelve years old, Sam discovered real love, non-platonic and burning hotter than fire. Everything he did from that moment on, he did for Dean, to impress him or protect him or make him happy. Going to Stanford broke his heart, but if Dean and their father ever found out, he'd be in a world of trouble. And when Dean showed up to whisk him back to their old life of adventure, violence, and death, Sam couldn't be happier, because he was by Dean's side again. Even through the horrible things that had happened to the both of them, Sam's love for Dean consumed him every day, and he fought to stay sane.

When Castiel had showed up, Sam was hit with a train. This being before him, an actual angel, wings and all, sent shivers up his spine and made his toes curl with one look. Sam felt awe, desire, and a feeling that could blossom into something like what he felt for his brother. It crushed him when Cas called him an abomination, and he fought tooth and nail to prove that he wasn't- That he could be more. Eventually he succeeded. Cas had given him that hard stare and told Sam he would give his life for him. Sam thought he was going to cry. It was more than just a crush.

In the Men of Letters bunker, he and Dean received separate rooms, which hadn't happened in a long time. Cas hadn't received his own room though; he elected to stay with Dean. Sam knew about their relationship, but the walls were thinner than he thought, and he learned more about those two than he had ever imagined he could.

They had a surprisingly active sexual relationship. The spectrum of their activities went from breaking furniture and leaving angry red marks on each others' bodies to lit candles and whispered sweet nothings, and Sam was right behind the wall, observing it all.

Thanks to one particularly violent session of love-making, there was a crack in Dean's door, barely big enough to see through, but Sam couldn't resist. One evening, when they were mostly quiet, Sam peered through the little crack as quietly as he could. The sight was beautiful: Cas, spread wide and open for a hungry Dean, three fingers in Cas' hole and an experienced tongue on his member. Sam's eyes traced the gorgeous curves of Dean's muscles, from his feet to his artfully tousled hair. He saw Cas' beautiful form taken over by pure need. He couldn't resist palming himself through his jeans. Cas' face screwed up in pleasure as Dean worked him over made Sam come the first time. The second time, it was Dean's noise as he came into Cas. The third was the sight of Dean riding Cas in a reverse-cowgirl style. Sam could see absolutely everything. He learned how to keep quiet, how to clean himself up quickly and get into his room before either of them came down from their blissed-out state. In short- Sam was a professional peeping Tom.

After several weeks of this nearly every night, Dean absentmindedly hung a robe on his door. Sam saw it when Dean woke up in the morning. "Morning, Sammy," he stretched, throwing the door open wide. Sam eyed the robe, which covered his precious peep hole. "It's dirty," Dean said, walking with Sam to the kitchen. "I'll clean it tomorrow or something." They made conversation about a possible Vetala attack in Missouri.

Cas wore Dean's pajama pants to breakfast, as well as a t-shirt and his trench coat. "Do you have to wear that thing everywhere? It's breakfast, man," Dean smiled affectionately at the angel.

Cas looked down at himself and removed the trench coat, looking at it strangely. "Where do I put it?" he asked.

"A coat rack is a good place to start," Dean pointed with the spatula at the front room where a perfectly good coat rack stood. Cas passed him, coat in hand, and Dean smacked his ass. Sam's eyes widened and he nearly choked on his juice. It was a regular occurrence in private, but they had never done it blatantly in front of Sam.

When Cas returned, he kissed Dean on the cheek and ruffled his hair before sitting next to Sam. Very close to Sam. "So Sam," the dark-haired man began. "I know you're very knowledgeable about this kind of creature. What do you think our next step should be?" They both looked at Sam expectantly. Sam was surprised; Dean usually led the planning, and Sam just supplied information. "Well," he murmured as Dean slid a plate of pancakes in front of him. "We should find a pattern on the victims. That'll tell us where they'll strike next."

They discussed the plan that Sam came up with and took care of the snakes quickly and efficiently. Dean didn't argue about Sam's plan, and Cas stuck to it and didn't pop out on them. It made Sam feel good.

That night, the robe still covered his only access to the room, so Sam sat in his own room with his ear to the wall. They were quiet tonight, and that frustrated him to no end. He had no visual, nearly no audio, and his hand wrapped around his leaking cock wasn't enough for him. He woke up tense and aching. In the kitchen, Dean was making Sam's favorite: omelets. He set the plate beside him, arms flexing right in front of his face. "You okay there, Sammy? You look tense," Dean said softly, his hand coming up to rub Sam's back.

Sam relaxed into his brother's touch. "Just didn't sleep well, but I'm fine," he murmured, lost in Dean's back rubbing. Dean ran his fingers through Sam's long hair affectionately before leaving to drag Cas out of his bed. Sam froze. That felt like more than a platonic touch between brothers. His scalp tingled and shivers ran up his spine. He noticed his heartbeat racing and tried taking deep breaths before the others came back in.

"Sam, are you okay?" Cas appeared in the kitchen, quickly followed by Dean.

"He just didn't sleep well," Dean explained for him, squeezing Cas' hand.

"But his face is red," Cas tilted his head to the side at Sam and he felt his face color even more. _Dammit, hold yourself together,_ he told himself.

Dean chuckled. "Omelet too hot for you?" _That's not what's too hot for me,_ he thought. Cas sat next to Sam again, very close. To someone across the room, Sam would probably look uncomfortable, though in reality he was just trying to hide his hard-on. Cas put a hand to his back casually and rubbed little circles as he watched the two humans eat. Sam was surprised, but any protests died in his throat. Dean didn't even blink. He smiled at the two and wolfed down his breakfast. First the hair touching and now the back rubbing? What the hell was happening?

"That was delicious, Dean," Sam smiled, stuffing the rest of the omelet in his mouth. "I need to go... do a thing," he mumbled hurriedly, ducking out from under Cas' hand and beelining for his room where he took care of a very big, very painful problem. Dean and Cas exchanged looks once Sam had darted out of the room.

"Tonight?" Cas asked.

"Tonight," Dean confirmed.

Sam and Dean were getting nowhere with their research. "We've seen some weird shit, but dinosaurs? Really?" Dean threw down another book and rubbed his eyes. "What would Bobby say?"

"He'd tell us to find a time machine and call us idjits," Sam sighed.

"Of course," Dean murmured. "I think I'm done for the night."

"I'm going to look some more. There's one more shelf I haven't sorted through yet." The taller Winchester rose and crossed the library to one of the many dusty old shelves. He kept his eyes peeled for _Dinosaurs, fossils,_ and even the word _Archaic_. He settled for a book called _Extinct Creatures and Beings_. He did not expect to find Dean nearly pushed up against him when he turned. "D-Dean?" Sam stuttered.

"Yeah, Sam?" Dean purred, gently untangling Sam's fingers from the book. Dean had been much more affectionate since moving into the Men of Letters bunker, but he never invaded his brother's space like this. Sam could feel the heat radiating off him.

"Weren't you going to bed?" Sam squeaked, mentally hitting himself for not keeping it together. The book was left, forgotten, on the library ladder.

"I will be soon," his voice was rough and low, and it made Sam shiver in the most delicious way.

Calloused fingers found Sam's hips and slid upwards, rucking his shirt up and pushing him gently back against the bookcase. "Dean-"

"Shh," Dean shushed him, brushing his full lips against Sam's jaw. It had to be a dream. This only happened in Sam's dreams, never in real life. He thought it was only him that had any of those feelings. But Dean was spoken for! Sam couldn't come between the two, even though he was so desperate with want that- "Stop thinking, baby boy," Dean commanded, nipping at Sam's ear. Sam couldn't help the tiny moan that slipped from his throat, from the action and the nick name.

Dean's arm snaked around Sam's waist, and his hand tangled in Sam's thick hair. Without a word, Dean kissed him ever so gently, lips hot and soft against his own. Sam didn't even try to resist. One hand clutched Dean's shoulder for dear life, as if he would fade away at any second. The other grasped at the front of his signature plaid flannel.

They fit together perfectly, and Sam felt Dean's very active member through his jeans. Dean grinned as he undoubtedly felt Sam's as well. "How long have you wanted this?" he whispered.

"So long," Sam breathed as Dean licked a strip of fire over Sam's jaw. "So, so long." Sam's head lolled backwards and his eyes closed. His hips twitched involuntarily as Dean reclaimed his mouth, tongue probing his own. When he came up for air, he made the mistake of opening his eyes. "Oh my god, Cas!" Sam's eyes widened in fear, and he immediately let go of Dean. The trenchcoated angel watched them with a blank expression. Dean did not let go; on the contrary, he rutted against Sam again.

"Hey Angel," Dean threw back over his shoulder.

"Hello Dean. Sam." Cas casually walked up to his boyfriend and his boyfriend's brother tangled in each other.

"Cas, I'm... I didn't..." Sam didn't know what to say or do. He was frozen. Dean grinned at Cas and removed his hands from Sam's waist. The blue-eyed angel's replaced them. "W-What?" Sam's mouth hung open as Cas squeezed his skin and pushed him back into the bookcase. Cas said nothing, but sealed his lips over the very confused younger Winchester.

Cas was more forceful than Dean. He nipped at Sam's bottom lip and drew his blunt nails down Sam's back. His tongue was more eager to take what it wanted, what Sam was happy to give.

"You two look so hot," Dean murmured, and Sam melted a little. He whimpered when Cas pushed his knee in between Sam's legs.

When Cas pulled off to make his own mark on Sam's throat, Sam choked out, "What's going on?"

"We know you've been watching us," Dean murmured, sliding his hand up the back of Sam's shirt.

"We've been, as Dean says it, 'putting on a show' for you," Cas' gravely voice explained.

"And we want you to join us," Dean's lips twitched up in a sly smile. Both men stepped back to let Sam breathe.

There was most certainly not enough blood in Sam's brain to work through the information. Both Dean _and_ Cas wanted him? Together? At the same time? Sam's breath came out in hard pants, almost as if the sex was already happening.

"Sammy?" Dean's voice snapped Sam's eyes up to him. "What do you say?"

"_Yes,"_ Sam immediately croaked, his voice breaking embarrassingly. He cleared his throat. "Uh, yes, I will, um, join." He felt so stiff and awkward accepting like that until both men in front of him grinned devilishly. Dean grasped Sam's left hand while Cas took the right and together the lovers dragged Sam down the hall and into their room.

Sam was actually thrown onto the large bed. He watched, transfixed, and Cas sealed his lips over Dean's and kneaded his ass in his hands. Dean moaned low into Cas' mouth. Once the angel had rid the older Winchester of his shirt, Sam reached down to palm himself through his jeans.

"Don't you dare," Cas' voice growled at him, his gaze fixed onto Sam. "You will not touch yourself, or you will be punished." Sam's eyes widened, a bit in fear and a bit in arousal.

"Mmm, he's good at punishment," Dean grinned, ripping the white dress shirt off the angel. Sam balled his hands into fists and whimpered at the sight of the two gorgeous men.

Once both of them were down to nothing but their boxers, they turned their attention to Sam. "You ever done this before, Sammy?" Dean said gently, straddling Sam and working on the buttons on his flannel. Cas lay next to Sam, one hand brushing through his hair and lips trailing kisses down his jaw.

"D-Do you mean with a guy or the threesome?" Sam gave a breathless laugh as Cas nipped at his ear. "No to either."

"We'll be gentle," Dean promised, pulling Sam's shirt off from under him. When Dean slid down to work off his pants, Cas' lips moved to Sam's. They were like satin, and Sam drowned in them as Dean pressed fiery kisses to Sam's hips. With all of the sensation, Sam was a little worried he'd finish from the gentle touching alone.

"Patience, baby boy," Dean murmured as Sam accidentally bucked his hips up. Sam glanced at Dean's head between his legs, hovering his aching length. When it twitched at the sight, Dean grinned and tore the jeans off, kneading Sam's thighs as Cas tweaked a nipple.

"You make amazing sounds," Cas growled in Sam's ear, tugging roughly on his hair to tilt his head up. Sam was vaguely aware of his boxers being removed, but was distracted by the angel's probing tongue.

When Sam felt hot wetness on his member, he bit Cas' lip. That was most definitely Dean's tongue, licking teasing stripes of electricity up his length. "Deeeean," he heard himself moan. Cas then straddled Sam's chest, his now-uncovered erection right in Sam's face. Sam had never given a blow job before, but he definitely wanted to. He took Cas into his mouth, the taste of his skin surprisingly pleasant. Dean's mouth closed completely around him and Sam moaned around Cas. The angel thrust shallowly into Sam's mouth, mindful of the awkward angle.

Dean was so talented with his tongue; it pressed against the bottom of Sam's length as he hollowed out his cheeks, the suction sending tingles up his spine. Dean seemed to have no gag reflex and no problem swallowing Sam down to the root. Sam couldn't see him behind Cas' torso, and while he wanted to, the lack of sight made each small movement that much more exciting.

Cas pinned Sam's wandering hands above his head and changed his angle, fitting himself more comfortably into Sam's mouth. Sam sucked greedily, as if this would never happen again. He felt warmth pooling in his stomach all too soon and released Cas from his mouth. "Cas, Dean, stop, I'm going to... fuck, I'm going to..." Dean's hand cradled his balls and Cas yanked roughly on Sam's hair.

"Come for us, Sam," Cas purred and Sam came hard into Dean's mouth, lightening shooting through his nerves. Dean swallowed every bit, licking Sam gently as he came down. The pull in his hair turned into a caress, the angel pushing back his locks affectionately.

"Ungh," Sam breathed, unable to form words.

"Cas, baby," Sam heard Dean say and felt the bed dip next to him. "Mmm, have a taste of Sam." His eyes opened just in time to see Dean and Cas' tongues intertwine, the taste of Sam shared between them. Sam's spent member twitched valiantly and he groaned.

Dean grinned down at his brother. "Ready for round two, baby boy?" Dean asked as Cas moved himself off Sam's chest.

"One..." Sam choked out. "One minute." Cas' hand was now trailing down his chest and stomach, the little movements powerful on Sam's over-sensitive skin. Dean kissed him softly, lips trailing down his jaw.

"You're so gorgeous, Sammy," Dean breathed in the taller Winchester's ear. "More than we thought, and we've always thought you were gorgeous." He nipped at Sam's ear and he felt himself filling up again. Cas' fingers trailed lower and lower until he brushed Sam's now full erection.

He let out a breathy sigh, another twinge of need rocketing through him. "Move forward, Sam," Cas commanded gently, moving to sit back on his knees behind Sam's head. Sam reached up and touched Cas' upside-down face for the first time, the angel turning to place a kiss on Sam's thumb. "Tell Dean if you need him to stop, alright?"

Dean had positioned his face once again over Sam's throbbing member, his ass over Sam's head. Cas' hands reached up and squeezed Dean's cheeks, parting them for Sam to see. Sam had just the right angle to see all of Dean, just out of reach above him. Dean's teeth nipped Sam's inner thigh as he passed the angel a little bottle of lube.

Sam's eyes widened a bit; he knew what was coming next. Or he thought he did. A smooth digit circled his hole and an aborted moan caught in his throat. _Relax,_ he told his muscles. Dean's finger kept up the gentle circles, not yet exploring further, and Sam relaxed into the soothing touch. Movement above him snapped his eyes upwards just in time to see Cas' tongue lave over the older Winchester's tight entrance. He nearly felt his pupils dilate as the angel repeated the motion, Dean's desperate whimpers vibrating through Sam's hips.

"Fuck," Sam heard himself whisper. Cas' tongue danced along Dean's entrance, Dean's fingers slow and steady against Sam's. Sam hardened even more, to his disbelief. After several minutes of this, Sam's hips were bucking against Dean's finger. "Dean!" he whined. "Please!"

"Cas?" Dean asked. Sam didn't understand the question until the angel slicked up a few of his fingers and traced the little pink bud. Dean hummed contently and arched his back. "Yes," he breathed.

Sam watched, riveted, as Cas' finger slowly pushed into Dean, lips parted and breathing heavily. Suddenly, the pressure of Dean's finger increased until Sam's first ring of muscle was breached. The intrusion was strange, but with the recent orgasm and prolonged stroking, Sam didn't tense.

"Breathe, ugnh, Sammy," Dean kissed Sam's hip as Cas' finger disappeared. Sam let out the breath he didn't know he was holding and allowed Dean's digit to slip into his tight space. "Fuck, Sam," Dean nipped his skin. "You're so tight." Sam breathed through the strange feeling. It wasn't unwelcome, just... foreign. He watched as Cas withdrew his finger from Dean and pressed it back in, twisting just so. "Cas," Dean moaned, hips twitching. "Uhhh, more."

Dean pressed into Sam again, keeping his movements slow as Cas sped up. The intrusion morphed from strange to good, and quickly to wonderful. Cas hit some spot inside Dean and he cried out, pushing roughly into Sam. He must have touched the same thing in Sam, because fire rocketed up his spine and he keened, high pitched and needy.

Cas hummed contently, speeding his fingers up inside Dean. Dean kept his movements slow and it was driving Sam insane. "Dean, please!" he bucked his hips up to find the spot again. Mercifully, Dean's movements quickened and he added another finger. The Winchesters moaned and writhed under Cas, whose eyes were completely black.

Dean gave Sam exactly what he was getting from Cas, striking that magic point inside until Sam felt the familiar pool of heat in his abdomen. "Not yet," Cas commanded, and Dean immediately withdrew his fingers. Sam felt so empty; he needed to fill that fullness again.

Dean and Cas hauled Sam's needy, itching body up to fit between theirs. Cas' lips found Sam's again, and even with a hand fisted in his hair, he was slow, purposeful. Dean's hands kneaded his back, peppering kisses along his neck and shoulders. Sam was practically vibrating with need. "Dean, Cas, please," he panted.

"We got you, Sammy," Dean pulled Sam up onto his knees on top of the bed, mimicking his position. He heard shuffling behind him as Cas moved, but Dean's firm hands traveled down to his ready and waiting hole, skirting teasingly over the edges.

"Fucking tease," Sam breathed. Dean's giant grin was infectious.

Cas' warm hands appeared on Sam's hips behind him. "Tell me if I need to stop, Sam," the angel's voice purred behind him. Cas' legs pushed between Sam's kneeling ones and he was pulled back against the blue-eyed man's chest, reclining slightly. Something silky and hot poked at Sam's entrance and he once again willed his muscles to relax.

"Please, Cas." Sam marveled at how he could sound so needy for a second, but then a diamond-hard member was pushing into Sam and _god_ it was huge. It burned, more than Sam thought it would, but Dean pushed his fingers through Sam's hair and murmured praise.

"So good, baby boy, you're doing so good," the older Winchester praised, distracting the younger with his lips. When Sam was fully seated on Cas, the angel froze. Sam hadn't known what full was until that moment. He was whole, complete, and burning from the inside out in the most delicious way. It didn't take long for his muscles to acclimate.

As a sign to continue, Sam dug his fingernails into Cas' thigh and pulled Dean into a messy kiss. The angel let out a deep growl and rolled his hips up into Sam. "God, so beautiful," Dean murmured against Sam's lips, fingers intertwining with Cas'. Cas shifted his weight and hit the magic button inside Sam. It was like lightening shooting to his core- he cried out. "FuckyespleaseCasmore," he babbled.

The angel stilled and Sam whimpered. More, he needed _more_. He opened his eyes in time to see Dean straddle them both and hover above Sam. "I've got you, baby boy, I've got you," he murmured. He sunk down entirely on Sam in one thrust, and Sam saw stars. Dean's walls squeezed him so tightly. How did he even fit in there? And then Dean moved and Sam lost all coherent thought.

Dean had one hand fisted in Cas' hair and one gripping Sam's shoulder for leverage. "Fuck, Sam, you're so big," the older Winchester grunted, lifting himself up and sinking back down on his brother. When Dean rose up and dropped down again, Cas pulled out and pushed back in. Sam couldn't describe the sensation if he tried. It was better than he had ever felt, possibly in his entire life. A rhythm was soon established.

Cas' moans were deep and throaty. Sam's were high pitched and needy. Dean swore and begged and praised the two. Noises filled the room, the perfect accompaniment to the sensations shooting through their bodies.

It was too soon that Sam felt the fire pooling in his center. He tried to warn Dean and Cas about his impending orgasm, but it hit him so hard that he couldn't breathe. Every sense but touch faded away, the nerve endings in his body firing at the speed of light. The thick spurts he felt from Cas pushed another wave over him, and the hot ropes on his stomach from Dean pushed another.

After a very long time, Sam came down, panting and sweating like crazy. Dean pulled himself off with a groan and helped Sam off of Cas. They teetered for a second, then crashed onto the mattress in a mess of sweat and come. With a wave of the angel's hand, the mess was gone.

Dean turned into Sam, throwing his arm over his waist. Cas traced patterns across his chest. The three lay like that for a long while waiting for their breathing to even out and their blood to pump at a normal speed.

"I love you," Sam murmured. "Both of you."

"I echo that sentiment," Cas hummed. "You two are the most perfect beings- angel, human, or otherwise."

"I'd normally call you two girls for being so sappy, but-" Dean sighed contently. "I'm too happy now to do that." Sam's eyes began to drift shut. "Angel, could you get us a blanket? And maybe kill the lights?" Cas lifted a finger and a soft blanket dropped on top of them, the room cloaked in darkness.

Sam pulled the two men closer to him, marveling at how the Righteous Man and an Angel of the Lord were both wrapped around him. "This was a good idea," he mumbled through a smile, two sets of quiet laughter beside him.


End file.
